Abstract: A semi-conductor thermal protection arrangement is disclosed for use with class AB, B, or C power amplifiers or in any other circuit configuration wherein a reduction in drive signal at a stage prior to that of the protected semi-conductor results in a lessening of the protected semi-conductor dissipation. The arrangement comprises a temperature sensor thermally coupled with the protected semi-conductor for detecting the absolute temperature of the semi-conductor and electrically connected so as to reduce the drive signal of the semi-conductor when the temperature of such semi-conductor exceeds a predetermined temperature above the normal operating temperature of the semi-conductor.